This invention relates to automatic motion picture cameras which include an electronic automatic exposure system. In the past such systems have included a galvanometer type motor for automatically closing the iris of the lens in accordance with the incoming light. Such motor systems were fragile and therefore subject to damage caused by rough handling of the camera or wear and tear resulting from ordinary use. In an effort to improve upon such systems a servo motor was added to permit the use of rugged components and bearings which would overcome the aforementioned problem. This use of a servo motor effectively circumvented the reliability problems but added a new problem in that excessive power consumption was required if such a system was permitted to stay on when the camera was not being used to feed film for shooting. It was necessary to leave the automatic electronic exposure control on because the camera would not be ready to shoot on an instantaneous basis without having the iris preset. A number of techniques were applied in order to overcome the high power consumption of the rugged automatic electronic exposure control while maintaining the camera in ready condition. For example, double switches were applied to the camera such that the automatic electronic exposure control would have to be energized first before the trigger which operated the film advance could be turned on. Even though such switching was relatively effective in conserving power, delays occurred in starting the shooting and a certain level of spontaneity was lost as a result. Consequently, the ability to film the scene instantaneously was prevented by those systems.